Addressing fatigue in cancer survivors using cognitive behavioural therapy for insomnia: a secondary analysis of a randomized controlled trial

Abstract

Cancer-related fatigue is frequently experienced by cancer survivors and is often comorbid with insomnia, perceived cognitive impairment (PCI), depression, and anxiety. This project consisted of 132 cancer survivors randomized into a treatment or waitlist control group. This thesis examined whether cognitive behavioural therapy for insomnia (CBT-I) can also improve fatigue among cancer survivors with insomnia disorder and PCI. The first study examined the efficacy of CBT-I for fatigue. Fatigue was measured using the Multidimensional Fatigue Symptom Inventory- Short Form. The treatment group experienced a 20.6-point reduction in fatigue compared a 3.7-point reduction in the waitlist control group, after statistically adjusting for improvements in comorbidities. Within-group mediation analyses demonstrated that improvements in fatigue were fully mediated by improvements in insomnia, PCI, depression, and anxiety. The second study (within-group) examined which factors were associated with a significant improvement in fatigue after CBT-I, defined as a decrease of 10.79 points on the fatigue measure. Three out of four participants (75%) experienced a significant reduction in fatigue. Younger participants (under 55 years) were more likely to experience improvement in fatigue after CBT-I. Considering the efficacy of CBT-I for fatigue in the current study, future research should focus on using CBT-I for fatigue and other negative symptoms experienced among cancer survivors.